Waving Turkish flags, women shouted "Of course, Yes!" ahead of the April 16 vote on constitutional changes that would give Turkey an executive presidency similar to political systems in France or the United States.

Erdogan's ruling Justice and Development Party (AKP) is running the "Yes" campaign, saying the changes would bring political stability. The vote is widely seen as a referendum on Erdogan himself because the proposed plan could see him stay in power until 2029.

Opponents however say the changes that would grant sweeping new powers to the head of state would make parliament dysfunctional and promote a one-man model.

Pro-government supporters gathered at the 12,500 capacity sports complex, known as Abdi Ipekci Arena, outside Istanbul's ancient city walls, with the campaign theme: "Yes! If women are there, democracy is there."

Erdogan himself, together with his wife Emine, showed up for the event organised by the pro-government Women and Democracy Association (KADEM), whose deputy chair is Erdogan's younger daughter Sumeyye Erdogan Bayraktar.

"For the survival of our country, it is a very important decision," said AKP supporter Ayse Gurcan, who came to the rally from Erzurum province in eastern Turkey.

"We must make our choice in a healthy way and I believe that everyone will say 'Yes'," she said